School of Mathematics and Physics - UQ eSpace
http://espace.library.uq.edu.au/
The University of QueenslandenFez http://blogs.law.harvard.edu/tech/rssAn introduction to quantum optomechanics
http://espace.library.uq.edu.au/view/UQ:269069
We provide an introduction to the description of mechanical systems in the quantum regime, and provide a review of the various types of micro-scale and nano-scale optomechanical and electromechanical systems. The aim is to achieve quantum control of micromechanical and nanomechanical resonators using the electromagnetic field. Such control requires the demonstration of state preparation (in particular, cooling to the ground state), coherent control and quantum-limited measurement. These problems are discussed in turn. Some particular problems in force detection, metrology, nonlinear optomechanics and many-body optomechanics are also discussed.2012-03-06T09:05:18Z
Milburn, G. J.; Woolley, M. J. An inverse theorem for the restricted set addition in Abelian groups
http://espace.library.uq.edu.au/view/UQ:268790
2012-03-02T10:48:25Z
Karolyi, G An investigation of contact transmission of methicillin resistant-Staphylococcus aureus
http://espace.library.uq.edu.au/view/UQ:70005
Hand hygiene is critical in the healthcare setting and it is believed that methicillin-resistant Staphylococcus aureus (MRSA), for example, is transmitted from patient to patient largely via the hands of health professionals. A study has been carried out at a large teaching hospital to estimate how often the gloves of a healthcare worker are contaminated with MRSA after contact with a colonized patient. The effectiveness of handwashing procedures to decontaminate the health professionals' hands was also investigated, together with how well different healthcare professional groups complied with handwashing procedures. The study showed that about 17% (9-25%) of contacts between a healthcare worker and a MRSA-colonized patient results in transmission of MRSA from a patient to the gloves of a healthcare worker. Different health professional groups have different rates of compliance with infection control procedures. Non-contact staff (cleaners, food services) had the shortest handwashing times. In this study, glove use compliance rates were 75% or above in all healthcare worker groups except doctors whose compliance was only 27%. (C) 2004 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.2007-08-15T03:28:42Z
McBryde, E. S.; Bradley, L. C.; Whitby, M.; McElwain, D. L. S. An investigation of evaporation from single saline water droplets: experimental and theoretical approaches
http://espace.library.uq.edu.au/view/UQ:350313
2015-02-02T08:48:26Z
Sadafi, M. H.; Jahn, I.; Stilgoe, A. B.; Hooman, K. Anisotropic scattering in angular-dependent magnetoresistance oscillations of quasi-two-dimensional and quasi-one-dimensional metals: Beyond the relaxation-time approximation
http://espace.library.uq.edu.au/view/UQ:173701
The electrical resistivity for a current moving perpendicular to layers (chains) in quasi-two-dimensional (2D) [quasi-one-dimensional (1D)] metals under an applied magnetic field of varying orientation is studied using Boltzmann transport theory. We consider the simplest nontrivial quasi-2D and quasi-1D Fermi surfaces but allow for an arbitrary elastic collision integral (i.e., a scattering probability with arbitrary dependence on momentum transfer) and obtain an expression for the resistivity which generalizes that previously found using a single relaxation-time approximation. The dependence of the resistivity on the angle between the magnetic field and current changes depending on the momentum dependence of the scattering probability. So, whereas zero-field intralayer transport is sensitive only to the momentum-averaged scattering probability (the transport relaxation rate), the resistivity perpendicular to layers measured in a tilted magnetic field provides detailed information about the momentum-dependence of interlayer scattering. These results help us to clarify the meaning of the relaxation rate determined from fits of angular-dependent magnetoresistance oscillations (AMROs) experimental data to theoretical expressions. Furthermore, we suggest how AMRO might be used to probe the dominant scattering mechanism.2009-04-03T13:01:51Z
Smith, M. F.; McKenzie, R. H. Anisotropy-based performance analysis of linear discrete time invariant control systems
http://espace.library.uq.edu.au/view/UQ:1481
2006-04-04T14:01:19Z
Diamond, P; Vladimirov, I; Kurdjukov, A; Semyonov, A Anisotropy in s-wave Bose-Einstein condensate collisions and its relationship to superradiance
http://espace.library.uq.edu.au/view/UQ:341250
2014-10-07T00:19:51Z
Deuar, P.; Jaskula, J.-C.; Bonneau, M.; Krachmalnicoff, V.; Boiron, D.; Westbrook, C. I.; Kheruntsyan, K. V. Annals of Operations Research
http://espace.library.uq.edu.au/view/UQ:190205
2009-12-16T14:14:45ZAnomalous power laws of spectral diffusion in quantum dots: A connection to luminescence intermittency
http://espace.library.uq.edu.au/view/UQ:219909
2010-11-07T00:03:49Z
Plakhotnik, T; Fernee, MJ; Littleton, B; Rubinsztein-Dunlop, H; Potzner, C; Mulvaney, P Anomalous saturation effects due to optical spin depolarization in nitrogen-vacancy centers in diamond nanocrystals
http://espace.library.uq.edu.au/view/UQ:279171
2012-08-19T00:13:20Z
Chapman, Robert; Plakhotnik, Taras A non-Hopfian almost convex group
http://espace.library.uq.edu.au/view/UQ:163835
In this article we prove that an isometric multiple HNN extension of a group satisfying the falsification by fellow traveler property is almost convex. As a corollary, Wise's example of a CAT(0) non-Hopfian group is almost convex.2009-02-11T10:05:37Z
Elder, Murray J. A non-linear numerical model for stratified Tsunami waves and its application
http://espace.library.uq.edu.au/view/UQ:58168
2007-08-14T14:56:08Z
Imteaz, M.; Imamura, F. A non-reductive N = 4 superconformal algebra
http://espace.library.uq.edu.au/view/UQ:271117
2012-03-22T12:08:27Z
Rasmussen, J. An open-access online question generator with fully worked solutions
http://espace.library.uq.edu.au/view/UQ:252289
Mathematics staff at The University of Queensland have created an electronic question and solution generator that covers a wide range of fundamental mathematical, statistical and quantitative skills. This open-access system allows teachers and/or students of all grades to create an unlimited number of questions covering over 100 topics, ranging from order of operations through to calculus and linear algebra. The beauty and originality of this flexible electronic framework is that fully worked solutions are also included. This paper outlines the process of developing and testing the question generator and discuss evidence of its effective implementation.2011-09-20T11:49:35Z
Jennings, Michael; Adams, Peter An optically actuated surface scanning probe
http://espace.library.uq.edu.au/view/UQ:298968
We demonstrate the use of an extended, optically trapped probe that is capable of imaging surface topography with nanometre precision, whilst applying ultra-low, femto-Newton sized forces. This degree of precision and sensitivity is acquired through three distinct strategies. First, the probe itself is shaped in such a way as to soften the trap along the sensing axis and stiffen it in transverse directions. Next, these characteristics are enhanced by selectively position clamping independent motions of the probe. Finally, force clamping is used to refine the surface contact response. Detailed analyses are presented for each of these mechanisms. To test our sensor, we scan it laterally over a calibration sample consisting of a series of graduated steps, and demonstrate a height resolution of ∼ 11 nm. Using equipartition theory, we estimate that an average force of only ∼ 140 fN is exerted on the sample during the scan, making this technique ideal for the investigation of delicate biological samples.2013-04-30T16:15:17Z
Phillips, D. B.; Gibson, G. M.; Bowman, R.; Padgett, M. J.; Hanna, S.; Carberry, D. M.; Miles, M. J.; Simpson, S. H. An optical trap experiment to demonstrate fluctuation theorems in viscoelastic media
http://espace.library.uq.edu.au/view/UQ:298973
2013-04-30T16:16:29Z
Carberry, D. M.; Baker, M. A. B.; Wang, G. M.; Sevick, E. M.; Evans, Denis J. An optimal design for screening trials
http://espace.library.uq.edu.au/view/UQ:222309
2010-11-24T13:47:18Z
Wang, Y. G.; Leung, D. H. Y. An opto-magneto-mechanical quantum interface between distant superconducting qubits
http://espace.library.uq.edu.au/view/UQ:335573
2014-07-29T00:40:44Z
Xia, Keyu; Vanner, Michael R.; Twamley, Jason A Note on Gittins Indices for Pharmaceutical Research
http://espace.library.uq.edu.au/view/UQ:222308
2010-11-24T13:47:13Z
Wang, Y. G.; Gittins, J. A note on Kerr/CFT and free fields
http://espace.library.uq.edu.au/view/UQ:269836
2012-03-14T11:41:00Z
Rasmussen, J. A note on the existence and uniqueness of a bounded mean-reverting process
http://espace.library.uq.edu.au/view/UQ:185157
2009-10-22T13:23:08Z
Lesmono, D.; Pollett, P. K.; Tonkes, E. J.; Burrage, K. A note on the Hopf-Stiefel function
http://espace.library.uq.edu.au/view/UQ:268226
We give a short elementary proof for a formula for the Hopf-Stiefel function that was found recently by Plagne via additive number theory.2012-02-23T15:59:48Z
Karolyi, Gyula A note on the path-discrepancy of trees
http://espace.library.uq.edu.au/view/UQ:267822
2012-02-17T16:14:18Z
Barany, I.; Karolyi, Gyula A novel approach for biomarker selection and the integration of repeated measure experiments from two platforms
http://espace.library.uq.edu.au/view/UQ:309712
2013-09-19T12:48:12Z
Liquet, B.; Le Cao, K.; Hocini, H.; Thiebaut, R. A novel breeding programme for improved growth in barramundi Lates calcarifer (Bloch) using foundation stock from progeny-tested parents
http://espace.library.uq.edu.au/view/UQ:251770
Rapid genetic gains for growth in barramundi (Lates calcarifer) appear achievable by starting a breeding programme using foundation stock from progeny tested broodstock. The potential gains of this novel breeding design were investigated using biologically feasible scenarios tested with computer simulation models. The design involves the production of a large number of full-sib families using artificial mating which are compared in common growout conditions. The estimated breeding values of their paternal parents are calculated using a binomial probit analysis to assess their suitability as foundation broodstock. The programme can theoretically yield faster rates of genetic gain compared to other breeding programmes for aquaculture species. Assuming a heritability of 0.25 for growth, foundation broodstock evaluated in two years had breeding values for faster growth ranging from 21% to 51% depending on the genetic diversity of stock under evaluation. As a comparison it will take between nine and twenty-two years to identify broodstock with similar breeding values in a contemporary barramundi breeding programme.2011-09-11T21:28:14Z
Macbeth, Gilbert Michael; Palmer, Paul John A novel protocol-authentication algorithm ruling out a man-in-the middle attack in quantum cryptography
http://espace.library.uq.edu.au/view/UQ:190441
In this work we review the security vulnerability of quantum cryptography with respect to "man-in-the-middle attacks" and the standard authentication methods applied to counteract these attacks. We further propose a modified authentication algorithm which features higher efficiency with respect to consumption of mutual secret bits.2009-12-18T13:12:19Z
Peev, M.; Nölle, M.; Maurhardt, O.; Lorünser, T.; Suda, M.; Poppe, A.; Ursin, R.; Fedrizzi, A.; Zeilinger, A. An overview of Calanus helgolandicus ecology in European waters
http://espace.library.uq.edu.au/view/UQ:112357
We review current knowledge and understanding of the biology and ecology of the calanoid copepod Calanus helgolandicus in European waters, as well as provide a collaborative synthesis of data from 18 laboratories and 26 sampling stations in areas distributed from the northern North Sea to the Aegean and Levantine Seas. This network of zooplankton time-series stations has enabled us to collect and synthesise seasonal and multi-annual data on abundance, body size, fecundity, hatching success and vertical distribution of C helgolandicus. An aim was to enable comparison with its congener Calanus finmarchicus, which has been studied intensively as a key component of European and north east Atlantic marine ecosystems. C finmarchicus is known to over-winter at depth, whereas the life-cycle of C helgolandicus is less well understood. Overwintering populations of C helgolandicus have been observed off the Atlantic coast between 400 and 800 m, while in the Mediterranean there is evidence of significant deep-water populations at depths as great as 4200 m. The biogeographical distribution of C helgolandicus in European coastal waters covers a wide range of habitats, from open ocean to coastal environments, and its contribution to mesozooplankton biomass ranges from 6 % to 93 %. Highest abundances were recorded in the Adriatic and off the west coast of Spain. C helgolandicus is generally found in 9-20 degrees C water, with maximum abundances from 13-17 degrees C. In contrast, C finmarchicus is found in cooler water between 0 and 15 degrees C, with peak abundances from 0 to 9 degrees C. As water has warmed in the North Atlantic over recent decades, the range of C. helgolandicus and its abundance on the fringes of its expanding range have increased. This review will facilitate development of population models of C. helgolandicus. This will not only help answer remaining questions but will improve our ability to forecast future changes, in response to a warming climate, in the abundance and distribution of this important species. (c) 2005 Elsevier Ltd. All rights reserved.2007-09-19T17:31:53Z
Bonnet, Delphine; Richardson, Anthony; Harris, Roger; Hirst, Andrew; Beaugrand, Gregory; Edwards, Martin; Ceballos, Sarah; Diekman, Rabea; Lopez-Urrutia, Angel; Valdes, Luis; Carlotti, François; et al. Antireflection coating for improved optical trapping
http://espace.library.uq.edu.au/view/UQ:170393
An antireflection coating improves the trapping of high-index particles in optical tweezers by reducing the scattering force. This can allow the strong trapping of high-index particles that cannot normally be trapped, and the use of lower numerical aperture objectives while still obtaining strong trapping. The improvement is not overly sensitive to the refractive index or thickness of the coating.2009-03-18T10:33:02Z
Hu, Ying; Nieminen, Timo A.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina Anti-self-dual connections and their related flow on 4-manifolds
http://espace.library.uq.edu.au/view/UQ:163424
In this paper, we establish the existence of the maximal time for a smooth solution to the anti-self-dual (ASD) flow in vector bundles over a 4-dimensional compact Riemannian manifold M and present a different proof of the Taubes’ existence theorem on anti-self-dual connections on 4-manifolds.2009-02-09T14:00:14Z
Hong, M.-C.; Yu, Z. Anti-symmetrization reveals hidden entanglement
http://espace.library.uq.edu.au/view/UQ:186152
Two-photon anti-bunching at a beamsplitter is only possible if the photons are entangled in a specific state, anti-symmetric in the spatial modes. Thus, observation of anti-bunching is an indication of entanglement in a degree of freedom, which might not be easily accessible in an experiment. We experimentally demonstrate this concept in the case of the interference of two frequency-entangled photons with continuous frequency detunings. The principle of anti-symmetrization of the spatial part of a wavefunction and subsequent detection of hidden entanglement via anti-bunching at a beamsplitter may facilitate the observation of entanglement in other systems, like atomic ensembles or Bose–Einstein condensates. The analogue for fermionic systems would be to observe bunching.2009-11-15T00:01:25Z
Fedrizzi, Alessandro; Herbst, Thomas; Aspelmeyer, Markus; Barbieri, Marco; Jennewein, Thomas; Zeilinger, Anton An ultra-bright atom laser
http://espace.library.uq.edu.au/view/UQ:327278
2014-03-31T08:39:42Z
Bolpasi, V.; Efremidis, N. K.; Morrissey, M. J.; Condylis, P. C.; Sahagun, D.; Baker, M.; von Klitzing, W. An upper limit to the dry merger rate at 〈z〉 ∼0.55
http://espace.library.uq.edu.au/view/UQ:194323
2010-01-31T00:06:19Z
DE Propris, R; Driver, SP; Colless, M; Drinkwater, MJ; Loveday, J; Ross, NP; Bland-Hawthorn, J; York, DG; Pimbblet, K ANZIAM Journal
http://espace.library.uq.edu.au/view/UQ:94586
2007-08-23T14:40:27ZA p-adic supercongruence conjecture of van Hamme
http://espace.library.uq.edu.au/view/UQ:190974
2009-12-23T15:20:09Z
Mortenson, Eric A parallel implementation on GPUs of ADI finite difference methods for parabolic PDEs with applications in finance
http://espace.library.uq.edu.au/view/UQ:339905
2014-09-17T16:37:18Z
Dang, D. M.; Christara, C. C.; Jackson, K. R. A PDE pricing framework for cross-currency interest rate derivatives with target redemption features
http://espace.library.uq.edu.au/view/UQ:340869
We propose a general framework for efficient pricing via a partial differential equation (PDE) approach for exotic cross-currency interest rate (IR) derivatives, with strong emphasis on long-dated foreign exchange (FX) IR hybrids, namely Power Reverse Dual Currency (PRDC) swaps with a FX Target Redemption (FX-TARN) provision. The FX-TARN provision provides a cap on the FX-linked PRDC coupon amounts, and once the accumulated coupon amount reaches this cap, the underlying PRDC swap terminates. Our PDE pricing framework is based on an auxiliary state variable to keep track of the total accumulated PRDC coupon amount. Finite differences on uniform grids and the Alternating Direction Implicit (ADI) method are used for the spatial and time discretizations, respectively, of the model-dependent PDE corresponding to each discretized value of the auxiliary variable. Numerical examples illustrating the convergence properties of the numerical methods are provided.2014-10-01T11:55:00Z
Christara, Christina C.; Dang, Duy Minh; Jackson, Kenneth R.; Lakhany, Asif A phenomenological model of the superconducting state of the Bechgaard salts
http://espace.library.uq.edu.au/view/UQ:172870
We present a group theoretical analysis of the superconducting state of the Bechgaard salts, e.g., (TMTSF)2PF6 and (TMTSF)2ClO4 (TMTSF: tetramethyltetraselenafulvalene). We show that there are eight symmetry distinct superconducting states. Of these, only the (fully gapped, even frequency, odd parity, triplet) 'polar state' is consistent with the full range of the experiments on the Bechgaard salts. The gap function of the polar state is , where ψuk may be any odd parity function that is translationally invariant. This analysis also predicts that a phase transition, between two superconducting phases, occurs in weak magnetic fields.2009-03-31T12:56:21Z
Powell, B. J. A phosphorescent poly(dendrimer) with increased viscosity for solution-processed OLED devices
http://espace.library.uq.edu.au/view/UQ:217108
2010-09-26T00:01:43Z
Levell, Jack W.; Gunning, Jack P.; Burn, Paul L.; Robertson, Jeremy; Samuel, Ifor D. W. A photon-driven micromotor can direct nerve fibre growth
http://espace.library.uq.edu.au/view/UQ:265649
Axonal path-finding is important in the development of the nervous system, nerve repair and nerve regeneration. The behaviour of the growth cone at the tip of the growing axon determines the direction of axonal growth and migration. We have developed an optical-based system to control the direction of growth of individual axons (nerve fibres) using laser-driven spinning birefringent spheres. One or two optical traps position birefringent beads adjacent to growth cones of cultured goldfish retinal ganglion cell axons. Circularly polarized light with angular momentum causes the trapped bead to spin. This creates a localized microfluidic flow generating an estimated 0.17 pN shear force against the growth cone that turns in response to the shear. The direction of axonal growth can be precisely manipulated by changing the rotation direction and position of this optically driven micromotor. A physical model estimating the shear force density on the axon is described.2012-01-22T12:44:59Z
Wu, Tao; Nieminen, Timo A.; Mohanty, Samarendra; Miotke, Jill; Meyer, Ronald L.; Rubinsztein-Dunlop, Halina; Berns, Michael W. A photonic quantum gate based on electrically controlled strong cavity coupling between a single nanocrystal quantum dot and an ultra-high Q silica micro-cavity
http://espace.library.uq.edu.au/view/UQ:247891
We investigate the use of nanocrystal quantum dots as a versatile quantum bus element for preparing various quantum resources for use in photonic quantum technologies. The ability to Stark tune nanocrystal quantum dots allows an important degree of control over the cavity QED interaction. Using this property along with the bi-exciton transition, we demonstrate a photonic CNOT interaction between two logical photonic qubits comprising two cavity field modes each. We find the CNOT interaction to be a robust generator of photonic Bell states, even with relatively large bi-exciton losses.These results are discussed in light of the current state-ofthe-art of both microcavity fabrication and recent advances in nanocrystal quantum dot technology. Overall, we find that such a scheme should be feasible in the near future with appropriate refinements to both nanocrystal fabrication technology and micro-cavity design. Such a gate could serve as an active element in photonic-based quantum technologies.2011-09-08T22:58:56Z
Fernee, Mark J.; Rubinsztein-Dunlop, Halina A Poincare-Birkhoff-Witt commutator lemma for U-q[gl(m vertical bar n)]
http://espace.library.uq.edu.au/view/UQ:64328
We present and prove in detail a Poincare-Birkhoff-Witt commutator lemma for the quantum superalgebra U-q[gl(m\n)]. (C) 2003 American Institute of Physics.2007-08-14T19:05:17Z
De Wit, D A polynomial embedding of pairs of orthogonal partial Latin squares
http://espace.library.uq.edu.au/view/UQ:330488
2014-05-20T02:19:21Z
Donovan, Diane M.; Sule Yazici, Emine Apparent Violation of the Wiedemann-Franz Law near a Magnetic Field Tuned Metal-Antiferromagnetic Quantum Critical Point
http://espace.library.uq.edu.au/view/UQ:173706
The temperature dependences of the interlayer electrical and thermal resistivity in a layered metal are calculated for Fermi liquid quasiparticles which are scattered inelastically by two-dimensional antiferromagnetic spin fluctuations. Both resistivities have a linear temperature dependence over a broad temperature range. Extrapolations to zero temperature made from this linear-T range give values that appear to violate the Wiedemann-Franz law. However, below a low-temperature scale, which becomes small close to the critical point, a recovery of this law occurs. Our results describe recent measurements on CeCoIn5 near a magnetic field-induced quantum phase transition. Hence, the experiments do not necessarily imply a non-Fermi liquid ground state.2009-04-03T13:09:28Z
Smith, M. F.; McKenzie, Ross H. Application of Bayesian model averaging to measurements of the primordial power spectrum
http://espace.library.uq.edu.au/view/UQ:230553
2011-02-28T12:00:07Z
Parkinson, David; Liddle, Andrew R. Application of gene shaving and mixture models to cluster microarray gene expression data
http://espace.library.uq.edu.au/view/UQ:134938
Researchers are frequently faced with the analysis of microarray data of a relatively large number of genes using a small number of tissue samples. We examine the application of two statistical methods for clustering such microarray expression data: EMMIX-GENE and GeneClust. EMMIX-GENE is a mixture-model based clustering approach, designed primarily to cluster tissue samples on the basis of the genes. GeneClust is an implementation of the gene shaving methodology, motivated by research to identify distinct sets of genes for which variation in expression could be related to a biological property of the tissue samples. We illustrate the use of these two methods in the analysis of Affymetrix oligonucleotide arrays of well-known data sets from colon tissue samples with and without tumors, and of tumor tissue samples from patients with leukemia. Although the two approaches have been developed from different perspectives, the results demonstrate a clear correspondence between gene clusters produced by GeneClust and EMMIX-GENE for the colon tissue data. It is demonstrated, for the case of ribosomal proteins and smooth muscle genes in the colon data set, that both methods can classify genes into co-regulated families. It is further demonstrated that tissue types (tumor and normal) can be separated on the basis of subtle distributed patterns of genes. Application to the leukemia tissue data produces a division of tissues corresponding closely to the external classification, acute myeloid meukemia (AML) and acute lymphoblastic leukemia (ALL), for both methods. In addition, we also identify genes specific for the subgroup of ALL-Tcell samples. Overall, we find that the gene shaving method produces gene clusters at great speed; allows variable cluster sizes and can incorporate partial or full supervision; and finds clusters of genes in which the gene expression varies greatly over the tissue samples while maintaining a high level of coherence between the gene expression profi les. The intent of the EMMIX-GENE method is to cluster the tissue samples. It performs a filtering step that results in a subset of relevant genes, followed by gene clustering, and then tissue clustering, and is favorable in its accuracy of ranking the clusters produced.2008-04-09T14:10:46Z
Do, K. A.; McLachlan, G. J.; Bean, R. W.; Wen, S. Application of the bootstrap approach to the choice of dimension and the a parameter in the SIRa method.
http://espace.library.uq.edu.au/view/UQ:309592
2013-09-17T12:39:43Z
Liquet, Benoit; Saracco, Jerome Applications of maximum principles to dynamic equations on time scales
http://espace.library.uq.edu.au/view/UQ:204292
2010-04-25T00:03:22Z
Stehlik, P; Thompson, B Applied dimensional problems in mathematics courses: how small-scale partnerships across disciplines can improve mathematical problem-solving skills of engineering students
http://espace.library.uq.edu.au/view/UQ:329152
2014-05-02T12:48:46Z
McCredden, Julie E.; O'Brien, Katherine R.; Roberts, Tony P. Applying matrix product operators to model systems with long-range interactions
http://espace.library.uq.edu.au/view/UQ:167097
An algorithm is presented which computes a translationally invariant matrix product state approximation of the ground state of an infinite one-dimensional (1D) system. It does this by embedding sites into an approximation of the infinite “environment” of the chain, allowing the sites to relax and then merging them with the environment in order to refine the approximation. By making use of matrix product operators, our approach is able to directly model any long-range interaction that can be systematically approximated by a series of decaying exponentials. We apply these techniques to compute the ground state of the Haldane-Shastry model [Phys. Rev. Lett. 60, 635 (1988) and Phys. Rev. Lett. 60, 639 (1988)] and present the results.2009-03-11T11:32:33Z
Crosswhite, Gregory M.; Doherty, A. C.; Vidal, Guifre Approach to frequency estimation in self-mixing interferometry: multiple signal classification
http://espace.library.uq.edu.au/view/UQ:303486
Based on the nature of self-mixing signals, we propose the use of the multiple signal classification (MUSIC) algorithm in place of the fast Fourier transform (FFT) for processing signals obtained from self-mixing interferometry (SMI).We apply this algorithm to two representative SMI measurement techniques:range finding and velocimetry. Applying MUSIC to SMI range finding, we find its signal-to-noise ratio performance to be significantly better than that of the FFT, allowing for more robust, longer-range measurement systems. We further demonstrate that MUSIC enables a fundamental change in how SMI Doppler velocity measurement is approached, letting one discard the complex fitting procedure and allowing for a real-time frequency estimation process.2013-06-23T00:14:00Z
Nikolic, Milan; Jovanovic, Dejan P.; Lim, Yah Leng; Bertling, Karl; Taimre, Thomas; Rakic, Aleksandar D.